J, H, Y, and LL
Most conventional rules say that Spanish J is pronounced as H. However, my name starts with a J and my Spanish teacher says it with a Y! In fact, he does that to every word that contains a J or a soft G (yeneral-general, Yermany-Germany, imayin-imagine, yas-just) . I know that in Spanish, y is sometimes pronounced with a j sound. So why doesn't he say my name with a J? Is he trying to confuse us and make us get bad grades on our oral test that he gives us? As a result, some of the students in my class think this strange logic. J=H, H=silent, so J=Silent. J=Y and J=H, so H=Y and Y=H. The complete equation: J=H=Y=LL=silent This leads to numerous pronunciation errors from my peers. However, I still say my Spanish J as H. What is the right way to say it?
4 Answers
The Spanish "J" is exactly like the German "ch" as "Bach" or Ach du lieber!
There are variants of the same. You get too close to a Spaniard and you might want to duck. 
Mexicans pronounce it a little less energetically. I have heard it said that the Spanish "J" sounds like the hacking sound that men make just before spitting. (lol)
The "Y" and the "ll" have variants from exactly the same as an English "y" through something that sounds a little like an English "J" to the Argentinian "y/ ll" which sounds like a cross between a French "j" and an English "sh." As pronounced in Spain is difficult to explain except it sounds a little like you're gagging, then quickly recover. If you know how to pronounce "Gyro" the way Greeks pronounce it. It's the same.
In Spanish the letter "h" is just a decoration. It is completely silent, unless preceded by "c" in which case, it's like the English "ch" as in "Charlie."
Welcome to the forum. Can you add your level of English and Spanish to your profile. It does help. I have assumed your English is advanced or fluent and Spanish beginner or intermediate.
The country where you are also helps - for example I am in the UK so tend to use British expressions and although I have visited a number of Spanish speaking countries I have more contact with music, tv films and people from Spain. For example I say c and z as th.
English tends to concentrate on consonants, whereas regional differences occur with vowels for example bath with a short a and with a long a . Spanish concentrates on vowels often running words together and losing the consonants.
Shakira says 'yo' with a soft j. I see from another answer your teacher is from Colombia. Shakira lives in Spain with her husband from Barcelona, but she was brought up in Colombia.
I learned to say j like the ch of loch [as pronounced by Scots] Sometimes it is softer. G in for example gente is pronounced the same way as j but has other ways of being pronounced depending which vowels follow eg guerra.
However you decide to speak, you should try and be consistent. Here is a link to videos by Jane Cronin. She is British but has lived in Spain a long time and is now teaching English people Spanish
If you want to look more deeply into pronunciation, the University of Iowa has information aimed at linguists
You can see how to shape your mouth and listen to someone saying the sounds. I have linked to 'fricative' which are the sounds you are interested in - just go down the list. You will also hear people from Spain and Argentina.
Most people I have heard say yo with a y but I have also heard it with a j. You never pronounce the h. Chat to your teacher.
Finally here is a brilliant song about the different ways Spanish is spoken. The singers are from Colombia and I find them very clear. I assume the people who live bordering the Caribbean have a different accent to people from Bogotá.
The link is to an article in veintemundos [a free electronic magazine - sign up for it]
Edit: If you look under viaje in the Veintemundos article there is a video about Colombian accents and the last video under multimedia is from Spain.
Typically, the English 'J' sound is completely foreign to most Spanish speakers. The only thing they can equate it to is the sound made with "i griega/ye" and "doble ele/elle". People don't realize how hard it can be to learn how to make the sounds of another language. Often times, it's easier to just do what you already know.
The letter "jota" can be pronounced as the English "H" and for most people learning Spanish from English, this suffices. It is either pronounced as a "Voiceless Velar Fricative" or "Voiceless Glottal Fricative", if you want to get into the phonology of it. Or you can just stick with the English pronunciation to keep it simple.
In some parts of the Spanish speaking world, "i griega/ye" and/or "doble ele/elle" are pronounced the way we pronounce the "s" in the word "pleasure" or the "sh" sound in "sharp".
To finish off: yes, "h" (hache) is ALWAYS silent.
